Mathematics often feels straightforward, yet some results challenge the way people instinctively think about numbers. Certain paradoxes and probability problems produce answers that seem impossible at ...

Editor’s Note: Published in 1957, this article comes from Martin Gardner’s legendary Scientific American column Mathematical Games. Read more in our special digital issue, Fun and Games. A paradox is ...

If two fair coins, a dime and a penny are flipped and you are told that the dime came up heads, then what is the likelihood that the penny comes up heads as well? Obviously 1/2. On the other hand, if ...

The correct technical definition of infinity is that it is equal to some of its parts. For example, both the set of all real numbers and the set of all even numbers have infinite elements, yet it is ...